According to the hornady concentricity tool I'm using, I'm getting about 0.0015" run out. I've got 2 sets of RCBS vintage 70's dies, a set of Lee, and a vintage set of Lyman with a PA seater die. The RCBS sets work the brass the least and then the Lyman. I use imperial neck lube applied with their media on each resizing. Case lube is RCBS # 2 on a pad. I decap in a dedicated die. When the case has entered the sizing die as far as desired and with the handle fully down, I adjust the sizing ball as far up as it will go and then back down 1 turn with the RCBS and Lyman. Don't lock down the lock nut-leave it loose so it will float and self center. That PA die is kinda like the new dimension dies from Hornady--it has a slider to align the case mouth with the bullet. Some say these dies are not precise enough to make a difference but my con gauge says other wise. When I got the PA die, the slider was marked 311. I found a set of Lyman for a 30-06 at a bargain and swapped out the slider to a 30 cal. I did keep the 311 in case I ever want to load oversized cast. Using RCBS sizer and the PA seater along with PPU brass, WLR primer, a charge of Varget a little less than the starting charge for a 170 gr, and a 190 gr barnes projectile seated to 2.522"-2.525, I'm regularly getting 4 shot groups touching at 50 YDS. The Lee set came with a shell holder that is listed for the 30-40 Krag and the 303 British. The only part of that set I use is the crimp die. With the bottom of it BARELY touching the holder, add 0.5 turn. When seating, again don't lock down the lock nut on the seating stem--let it float to self center like the expander stem. These groups are from an F model, 1929 manu, equipped with a WONDERFUL Light foot mount holding a vintage Redfield 2x7 widefield in 1" tall leupold rings. I'm shhoting it cross stock. This level of accuracy is not indicative of my skill but of the wonder of the right equipment. Case trimming is done with a Lee zip trim utilizing a case holder from a 30-30 and the actual trim shaft from a 308 Win set